Tug Operators Ask for More Water Depth in Snake Riverby Mike O'Bryant
Columbia Basin Bulletin - April 11, 2003
After three years of not dredging stretches of the lower Snake River, tugboat operators are worried their boats and tows will ground on sandbars and jeopardize the safety of their loads and crews. They asked the Technical Management Team this week to raise water levels in reservoirs to a depth of at least 14 feet.
While TMT agreed to temporarily raise reservoir levels, its members asked the tug operators, along with the U.S. Army Corps of Engineers and the U.S. Coast Guard, to bring to its next meeting more information on where, and how shallow, are troublesome areas in the river.
The operations requested by the Columbia River Towboat Association conflicts with NOAA Fisheries 2000 biological opinion, which calls for minimum operating pools (MOP) when spilling water to aid juvenile salmon and steelhead passage through the dams. Spill began last Thursday evening at Lower Granite Dam and then every two days at each dam in a row going downstream. The low water, according to NOAA Fisheries, increases the velocity of the water over the dam by 7 percent from the velocity of water when pools are full.
"We need more depth," Larry Johnson of Foss Maritime told TMT. "We carry all types of commodities and our worst fear is to rip out the bottom of an oil barge." Tug operators began noticing last year that they were touching bottom in some areas of the reservoirs.
Johnson said the barges already are "light-loaded" and that they cannot slow down more because a tugboat with a tow begins to lose steerage as it slows down. One of the more critical times is when the tug is leaving a lock and has little room to clear a sill from the lock to the upper reservoir. Critical areas in the navigation channel are at Schultz Bar in the Little Goose pool and from the entrance to the Snake River up through the Ice Harbor cut.
"Our concern is not with light-loading. We've had that for over a year," Johnson said. "Now our main concern is navigational safety and our ability to maintain operational control of the tug and tow. The best way to resolve all this is to dredge the system."
The Corps has not been able to dredge the lower Snake River channel since the winter of 1997-98. In recent times it has kept reservoir levels about a foot higher (MOP plus one) than is considered optimal for fish in order to allow the draft needed by the barges carrying farm produce and other products up and down the river. Last week, as it began spill at the dams, it set reservoir levels at the MOP level.
A U.S. District Court judge in Seattle issued in December 2002 a preliminary injunction prohibiting navigation channel dredging on the lower Snake River in response to a lawsuit filed in court by the National Wildlife Federation, Washington Wildlife Federation, Idaho Rivers United, Idaho Wildlife Federation, Pacific Coast Federation of Fishermen's Association, and the Institute for Fisheries Resources against the U.S. Army Corps of Engineers.
The court agreed with charges that the Corps' Environmental Impact Statement should have considered more options and it found deficiencies in NOAA Fisheries favorable biological opinion of the project. The court said the federal fisheries agency had failed to ensure that dredging would not destroy critical habitat for fall chinook salmon, as required by the law and the BiOp was rescinded. According to Chris Ross of NOAA Fisheries, the Corps and NOAA Fisheries are now reconsulting on the dredging operations and expect a BiOp sometime this summer.
Until better information on navigation channel depth is available, TMT agreed to increase pool levels at Lower Granite, Little Goose and Ice Harbor dams to MOP plus one, and to MOP at Lower Monumental.
Implementation Team: www.nwr.noaa.gov/1hydrop/hydroweb/rif.htm
Technical Management Team: www.nwd-wc.usace.army.mil/TMT/index.html
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